Conventionally, “stake tubes” and/or the port inside a booster are used as the fuel tube between a metering block and a chamber of the carburetor main body. These “stake tubes” are non-removably attached (spin welded, spin riveted, pressed, or glued) to the carburetor main body fuel intake port and then the inside of the stake tube is drilled out to the desired size. If the size needs to change or be adjusted, the carburetor must be replaced or the port in which the stake tube is inserted must be drilled out, a new stake tube spin welded or riveted in and then bored out to the correct size, or the booster assembly must be drilled or replaced. It is also common for the removal of the stake tube to cause damage to the booster assembly, destroying both parts.
The inside port in which the stake tube is fitted has a flat profile which mates with the flat profile of the stake tube to ensure full contact during spin welding. These stake tubes often need to be resized between races. In order to use fuel tubes with different sizes, the carburetor must be sent to a machine shop, the stake tube and/or booster drilled out, and a new stake tube and/or booster added and machined to the desired size. The other option has been for the entire carburetor to be completely replaced.